The present invention relates to the field of exercising devices.
There is a need for exercising the hands in order to strengthen them over a period of time. There is also a need for indicating the progress made over the time period to encourage the exerciser to continue with the exercising routine and note his or her progress. It is desirable to provide a single device for exercising both hands in a pleasant and rhythmic fashion over an exercising interval while noting the forces produced by each hand. The exercising intervals may be performed for several weeks or more, and thus by observing and recording the measured increases of impulse pressure due to the hand squeezing process, the hopefully improving hand strengths can be individually indicated for both the right and left hands.
It is also desirable to provide a single device that can be used in the manner described for exercising and indicating the substantial hand strengths of a strong body builder and the modest hand strengths of a frail elderly person with arthritis or a similar condition, and persons having hand strengths in between these two extremes.
The aforesaid desired desired goals have not been met by the prior art retrieved during our pre-examination search. Hallerman U.S. Pat. No. 4,222,560 discloses a plurality of exercising devices for squeezing fluids to accommodate various hand strengths, each device requiring different squeeze forces. Dikeman U.S. Pat. No. 4,114,449 discloses a hand exercising device employing a single fluid filled bulb that is squeezed by one hand. The greater the squeezing pressure, the greater the displacement of a hand squeezing pressure measuring indicating member by the fluid against the compressibility action of trapped air that resists the motion of the indicating member. Thus, the fluid under compression is blocked by the movable indicator. Smith U.S. Pat. No. 4,530,496 has a similar arrangement with an optional pressure gage G in FIG. 5. Again, the fluid under compression is blocked by the movable indicator. This is in sharp contrast with the present invention, whereby fluid is forced completely through a twin pair of valves that “self adjust” to the degree of squeezing pressure. This means that the single device of the present invention can be used to continuously exercise the hands of persons having widely varying strengths over a substantial time period for exercising the hands, whereas the devices of the latter two references are not conducive to exercising the hands, and certainly not two hands over a substantial time period.